Reinforced wood floor sections

ABSTRACT

Decking for roofs and floors, and a method of manufacture thereof, in which a decking section comprises a plurality of boards of forcibly bent configuration secured side-by-side and retained in their bent configuration by metal strips which may be provided with integral punched-out projections.

United States Patent Lindal [541 REINFORCED WOOD FLOOR SECTIONS [72] Inventor: Skuli Walter Lindal, 9004 S. 19th St., Tacoma, Wash. 98466 [22] Filed: Jan. 30, 1970 [21] Appl. No.: 6,990

[52] US. Cl. ..52/223, 52/222, 52/262, 52/715, 144/309 B [51] Int. Cl. ..FAHI) 5/12 [58] FieldofSearch ..52/223,225,240,282, 52/223- 226, 86, 640, 642, 644, 227, 715;

[56] References Cited UNITED STATES PATENTS 1,595,673 8/1926 Magney ..52/240 2,039,398 5/1936 Dye ..52/223R Aug. 29, 1972 Decking for roofs and floors, and a method of manufacture thereof, in which a decking section comprises a plurality of boards of forcibly bent configuration secured side-by-side and retained in their bent configuration by metal strips which may be provided with integral punched-out projections.

3 Claims, 4 Drawing Figures PATENTEDMIEZQ I 12 I 3.686.809

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1 REINFORCED WOOD FLOOR SECTIONS BACKGROUND OF THE INVENTION This invention relates to decking for roofs and floors.

. placed in tension and retain the boards in their forcibly In many buildings, particularly wood frame 5 buildings, the roofs and floors consist of spaced-apart joists running between walls of the building and decking laid across the joists. One commonly used form of decking has been tongueand-groove boards. These boards have been laid side by side across the joists and nailed to each joist. Such decking has been found to have a number of disadvantages. In the first place, individual boards are usually of comparatively narrow width so that laying of the decking takes an appreciable length of time. Secondly, the boards have been able to span only a limited distance between joists in order to avoid creating excessive tensile stresses in the lower chord of the boards in use. Wood has a limited tensile strength. Thirdly, tongueand-groove boarding is subject to racking. Racking is relative longitudinal slipping between adjacent boards. If decking is subject to racking, then it provides no transverse strength to the building. As a result of this last, disadvantage, there has been widespread adoption of large sheets of plywood decking insubstitution for the former tongueand-groove boards. The plywood sheets have a large area and are not subject to racking and provide transverse strength to the building.

SUMMARY OF THE INVENTION It is a general object of the present invention to provide decking composed of boards which overcomes the above mentioned disadvantages.

According to the present invention, a decking section comprises a plurality of generally plane-sided parallel longitudinally extending wood boards located side-by-side and metal strips extending between adjacent sides of the boards and secured to adjacent boards. The boards are forcibly bent about a longitudinal neutral plane of the boards and the metal strips are in tension and hold the boards in their forcibly bent configuration.

Preferably, the metal strips comprise integral punched-out portions forming securing means for entering the boards and securing the boards together.

The edge surfaces of each decking section can be formed with respective tongueand-groove configurations for assembly with a similar decking section.

The prestressed decking of the invention not only reduces the racking effect but also enables a wider spacing of joists to be utilized, since in comparison with non-prestressed boards of the same nominal size, increased loadings can be applied to the boards before too high a tension occurs in the boards. Furthermore, the decking sections can be preassembled in a plant to a size which is preferred for most economical and effi- I cient use on a site.

The invention also provides a method of manufacturing a decking section comprising locating a plurality of longitudinally extending wood boards in parallel sideby-side relation, and locating metal strips between adjacent sides of the boards. Bending forces are then ap plied to the boards about a longitudinal neutral plane of the boards to forcibly bend the boards. Then the metal strips are secured to adjacent boards and the bending forces are released whereupon the metal strips are bent configuration.

BRIEF DESCRIPTION OF DRAWINGS The invention will now described, by way of example, with reference to embodiments shown in the accompanying drawings in which:

FIG. 1 is an end elevation of a decking section according to the invention;

FIG. 2 is a section on line II-II of FIG. 1;

FIG. 3 is a top plan view of the decking section of FIG. 1; and b FIG. 4 is a view similar to that of FIG. 2 of a further form of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The embodiment of the invention shown in FIGS. 1 to 3, comprises two full'width boards 1 having a rectangular configuration formed by generally plane parallel sides and faces and two half-width boards 2 and 3 having two plane parallel faces and one plane side each, and the board 2 having its other side formed with a tongue and the board 3 having its other side formed with a groove.

The boards 1, 2 and 3 extend parallel to each other and metal strips 4 are located between adjacent sides of the boards The metal strips 4 have integral punchedout projections 5 which extend from each side Of the strips and which serve as securing rneans in that punched-out projections 5 extend. into the material of the adjacent boards.

As shown in somewhat exaggerated form in FIG. 2, the boards 1, 2 and 3 are bent about a longitudinal neutral plane of the boards. The metal strips 4 hold the board 3 and the other boards 1 and 2 in their bent configuration.

To manufacture a decking section as shown in FIGS. l to 3, the boards 1, 2 and 3 are first placed side by side, but spaced apart and with the metal strips 4 between adjacent sides of the boards. The boards are then subject to bending forces to provide the required degree of curvature. When the required degree of curvature has been obtained, the boards are moved toward each other so as to clamp the metal strips therebetween and to force the punched-out projections 5 into the material of the boards. The bending forces are then released at which time the boards attempt to regain the un-stressed condition but are restrained from so doing by the metal strips 4 which are placed in tension.

It is preferable to at least slightly tension the metal strips before securing them to the forcibly bent boards.

As indicated earlier, the decking of the present invention can be used with wider spacing of joists than with hitherto known board decking using a similar nominal size of board. This is because during manufacturing prestressing and application of the metal strip means that substantially increased! loading is required to introduce a tension force in the lower chord of the individual boards. Furthermore, the metal strips substantially rigidly secure the adjacent boards together so that the whole forms a monolithic piece of decking which can withstand racking forces and can serve to strengthen a wood building transversely of the building. Also, an increased area of decking can be obtained from the same amount of lumber. Since no tongue and grooving is provided the full width of each piece of lumber may be used. Furthermore, it is less expensive to machine plane-sided lumber than lumber having edges with tortuous configurations such as tongues and grooves.

FIG. 4 illustrates how a series of boards having a length to span three adjacent joists can be formed into decking according to the invention. As shown in FIG. 4, the board 11 has two curved portions 11a and 11b, each of the portions being the width of one span between joists 15. The board 11 is forcibly bent in the same direction in the portions 11a and 11b so as to obtain a double curved form. A metal strip 12 is placed along the portions 11a and 11b and serves to hold the individual portions 11a and 1 lb in their curved form. It would be possible to use two metal strips having a total length substantially equal to the whole length of the board 1 l and placed end-to-end along each of the portions 11a and 11b. The same principle may also be applied to three or more spans.

As an indication of dimensions, which may be used with the present invention, one useful embodiment contains four boards of 64 inch length consisting in two full-width boards of nominal size 2 inches by 8 inches and two half-width boards of nominal size of 2 inches by 4 inches. Approximately half an inch is lost in machining. The boards are provided with a quarter of an inch deflection in each 64 inches of length. The metal strip, in this case, is 1 inch wide and one-eighth of an inch thick and the punched-out projections have a length of 1 inch and a root width of one-eighth of an inch and are'spaced alternately along the upper and lower edges of the metal strip 1 inch apart.

It will be apparent that alternative means of securing the boards together could be used, but it has been found that the metal strip described above, is to be preferred in view of relative costs and efficiency in use.

I claim:

1. A decking section comprising a plurality of generally plane sided, longitudinally extending wood boards arranged in parallel side-by-side relationship; and a metal strip extending between each adjacent pair of boards in a plane parallel to the confronting longitudinal sides of said pair of boards; each said board being similarly pre-stressed by bending forces in a plane parallel to the plane of said metal strip; each said strip being secured to said confronting faces of the corresponding adjacent pair of boards, whereby each board is retained in its pre-stressed state and applies a tensile stress to said metal strip secured to a longitudinal side of that board.

2. A decking section according to claim 1 wherein each said metal strip includes integral punched-out projections extending laterally therefrom in planes generally transverse to the longitudinal direction of the metal strip, said projections extending into adjacent boards to secure said adjacent boards in substantially face-to-face relationship with said metal strip.

3. A decking section according to claim 1 wherein said bending forces are such that each said board is forcibly bent into at least two, longitudinally spaced curved portions. 

1. A decking section comprising a plurality of generally plane sided, longitudinally extending wood boards arranged in parallel side-by-side relationship; and a metal strip extending between each adjacent pair of boards in a plane parallel to the confronting longitudinal sides of said pair of boards; each said board being similarly pre-stressed by bending forces in a plane parallel to the plane of said metal strip; each said strip being secured to said confronting faces of the corresponding adjacent pair of boards, whereby each board is retained in its prestressed state and applies a tensile stress to said metal strip secured to a longitudinal side of that board.
 2. A decking section according to claim 1 wherein each said metal strip includes integral punched-out projections extending laterally therefrom in planes generally transverse to the longitudinal direction of the metal strip, said projections extending into adjacent boards to secure said adjacent boards in substantially face-to-face relationship with said metal strip.
 3. A decking section according to claim 1 wherein said bending forces are such that each said board is forcibly bent into at least two, longitudinally spaced curved portions. 